An imaging apparatus, such as an ink jet printer, forms an image on a print medium, such as paper, by applying ink to the print medium. The ink may be contained in one or more replaceable supply cartridges. Examples of such replaceable supply cartridges include a replaceable ink tank and an ink jet printhead cartridge. An ink jet printhead cartridge, for example, includes both an ink tank and an ink jet micro-fluid ejection device, whereas an ink tank does not include the micro-fluid ejection device.
One such ink jet printer mounts a plurality of ink tanks, with each ink tank containing a supply of a particular color of ink, e.g., black, cyan, magenta, and yellow. Each ink tank is mounted to a micro-fluid ejection device that is separately mounted to the printhead carrier, and is commonly referred to as an on-carrier ink tank system. In an on-carrier ink tank system, the ink is transferred from the tank to the micro-fluid ejection device through as series of fluid interfaces. The ink typically is suspended in the tank in a felt or foam. Care must be taken to ensure firm mounting of each removable ink tank in relation to the printhead assembly, so as to, for example, facilitate the formation of an adequate seal between each ink tank and the printhead assembly at the fluid interface.